less than 20% of childhood nystagmus is acquired, and it carries a significant risk of serious underlying pathology — in one large pediatric ED cohort, urgent conditions accounted for ~19% of acute nystagmus cases, with brain tumors representing 8.3%.[1][2]

The causes can be organized by mechanism and likelihood:

Common Causes

- Migraine/vestibular migraine — The most common cause of acute nystagmus in the pediatric ED (25.7%), often accompanied by headache and vertigo. Spontaneous nystagmus in adolescents with vestibular migraine tends to be variable in form.[1][3] - Peripheral vestibular disorders — Including vestibular neuritis and BPPV, accounting for ~14% of pediatric acute nystagmus cases. Characterized by unidirectional horizontal-torsional nystagmus, positive head impulse test, and suppression with visual fixation.[1][4][5] - Medication/substance-induced — Anticonvulsants (phenytoin, carbamazepine), sedatives, dextromethorphan, and alcohol/illicit substances are common culprits. Dextromethorphan is the most frequently reported drug causing nystagmus at poison control centers. Medication history is essential.[6]

Serious (“Cannot Miss”) Causes

- Intracranial tumors — Posterior fossa tumors (medulloblastoma, ependymoma, cerebellar astrocytoma) and anterior optic pathway tumors (optic nerve glioma) are the most common serious cause of acquired nystagmus in children. Vertical nystagmus (downbeat or upbeat) is particularly suggestive of posterior fossa lesions.[1][7][2][8] - Demyelinating disease (multiple sclerosis) — Can present as an acute vestibular syndrome in adolescents. Central oculomotor signs (direction-changing nystagmus, normal head impulse test, skew deviation) help distinguish it from peripheral causes.[9] - Posterior circulation stroke/hemorrhage — Rare at age 14 but possible with underlying vascular anomalies, coagulopathy, or cardiac disease. Cerebellar stroke can closely mimic vestibular neuritis.[10] - Infectious/inflammatory encephalitis — Brainstem or cerebellar encephalitis (viral, autoimmune/paraneoplastic) can produce nystagmus with other neurologic signs.

Other Important Causes

- Chiari malformation — Found in 3.4% of children undergoing MRI for nystagmus; typically causes downbeat nystagmus.[11][12] - Metabolic diseases — Leukodystrophies, mitochondrial disorders, and vitamin deficiencies (B12, thiamine) can present with acquired nystagmus.[7][8] - Hereditary/degenerative cerebellar ataxias — Episodic ataxia type 2, spinocerebellar ataxias, and [Friedreich ataxia](https://www.openevidence.com/rare-disease/friedreich-ataxia) may present in adolescence with nystagmus.[8] - Late-recognized congenital nystagmus — Occasionally, infantile nystagmus is not identified until adolescence; key distinguishing features include absence of oscillopsia and absent optokinetic nystagmus.[2]

Red Flags Suggesting Urgent Pathology

Cranial nerve deficits, ataxia, and strabismus are strongly associated with urgent underlying conditions in children with acute nystagmus.[1] Additional alarming features include oscillopsia, dissociated (asymmetric) nystagmus, papilledema, and afferent pupillary defect.[2]

Recommended Next Steps

Assuming a basic history and neurologic exam have been performed:

- Targeted history: Medication/substance exposure, headache pattern, prior neurologic episodes, family history of neurologic disease, and timeline of onset (acute vs. subacute vs. chronic). - Focused exam: Characterize the nystagmus (direction, effect of fixation, gaze-evoked vs. spontaneous), perform head impulse test and test of skew, assess for cranial nerve palsies, ataxia, papilledema, and visual acuity. - Initial workup:

1. MRI brain and orbits with contrast is the imaging modality of choice for acquired nystagmus in a child, recommended by the ACR Appropriateness Criteria. Among children with isolated nystagmus undergoing MRI, 15.5% had intracranial abnormalities.[7][12]
2. Ophthalmologic evaluation including fundoscopy and visual electrophysiology if visual pathway pathology is suspected.
3. Toxicology screen if substance exposure is a concern.

- Red flags for escalation: Vertical or direction-changing nystagmus, ataxia, cranial nerve palsies, or papilledema should prompt urgent neuroimaging and neurology consultation.[1][8][13]

Is there additional clinical context — such as the nystagmus characteristics (direction, intermittent vs. constant), associated symptoms, or medication history — that could help narrow the differential further?

### References

1. Characteristics of Acute Nystagmus in the Pediatric Emergency Department. Garone G, Suppiej A, Vanacore N, et al. Pediatrics. 2020;146(2):e20200484. doi:10.1542/peds.2020-0484.
2. Infantile and Acquired Nystagmus in Childhood. Ehrt O. European Journal of Paediatric Neurology : EJPN : Official Journal of the European Paediatric Neurology Society. 2012;16(6):567-72. doi:10.1016/j.ejpn.2012.02.010.
3. Clinical Significance of Spontaneous Nystagmus in Pediatric Patients. Zhou G, Goutos C, Lipson S, Brodsky J. International Journal of Pediatric Otorhinolaryngology. 2018;111:103-107. doi:10.1016/j.ijporl.2018.06.007.
4. Head Impulse, Nystagmus, and Test of Skew Examination for Diagnosing Central Causes of Acute Vestibular Syndrome. Gottlieb M, Peksa GD, Carlson JN. The Cochrane Database of Systematic Reviews. 2023;11:CD015089. doi:10.1002/14651858.CD015089.pub2.
5. Vestibular Neuritis. Baloh RW. The New England Journal of Medicine. 2003;348(11):1027-32. doi:10.1056/NEJMcp021154.
6. Common Ocular Effects Reported to a Poison Control Center After Systemic Absorption of Drugs in Therapeutic and Toxic Doses. Slattery A, Liebelt E, Gaines LA. Current Opinion in Ophthalmology. 2014;25(6):519-23. doi:10.1097/ICU.0000000000000103.
7. ACR Appropriateness Criteria® Orbital Imaging and Vision Loss-Child. Expert Panel on Pediatric Imaging, Maheshwari M, Ho ML, et al. Journal of the American College of Radiology : JACR. 2024;21(6S):S219-S236. doi:10.1016/j.jacr.2024.02.023.
8. Pearls & Oy-Sters: Positional Vertigo and Vertical Nystagmus in Medulloblastoma: A Picture Is Worth a Thousand Words. Kronenbuerger M, Olivi A, Zee DS. Neurology. 2018;90(4):e352-e354. doi:10.1212/WNL.0000000000004866.
9. Multiple Sclerosis as a Cause of the Acute Vestibular Syndrome. Pula JH, Newman-Toker DE, Kattah JC. Journal of Neurology. 2013;260(6):1649-54. doi:10.1007/s00415-013-6850-1.
10. Acute Vestibular Syndrome. Hotson JR, Baloh RW. The New England Journal of Medicine. 1998;339(10):680-5. doi:10.1056/NEJM199809033391007.
11. Incidence and Types of Pediatric Nystagmus. Nash DL, Diehl NN, Mohney BG. American Journal of Ophthalmology. 2017;182:31-34. doi:10.1016/j.ajo.2017.07.006.
12. The Role of MR Imaging in Investigating Isolated Pediatric Nystagmus. Batmanabane V, Heon E, Dai T, et al. Pediatric Radiology. 2016;46(12):1721-1727. doi:10.1007/s00247-016-3669-9.
13. Guidelines for Reasonable and Appropriate Care in the Emergency Department 3 (GRACE-3): Acute Dizziness and Vertigo in the Emergency Department. Edlow JA, Carpenter C, Akhter M, et al. Academic Emergency Medicine : Official Journal of the Society for Academic Emergency Medicine. 2023;30(5):442-486. doi:10.1111/acem.14728.

• AAO Clinical Guidelines by Dumitrescu AV
• AAO Video:Infantile Nystagmus